Clearance: vacating a square or line

Clearance of a square or line: what is it

Clearance is a tactic where you move your own piece off a square or line to make room for another one of your pieces. Without it, the decisive blow will not work.

There is square clearance (when a particular square needs to become empty) and line clearance (when you need to open a rank, file or diagonal for a long-range piece).

When clearance is used

  • Your own piece is in the way of mate: the rook wants to go to e8, but a white knight is standing there.
  • The line for a long-range piece is blocked by your own bishop or pawn, and the obstacle has to be removed.
  • A quiet move does not work: the clearance has to be made with tempo, with an attack, a check or a capture.

Why it works

In chess, each square can hold only one piece. If the key square for the attack is taken by one of your own soldiers, the winning idea "does not reach". One precise move, and the whole plan comes to life.

Important: the clearing piece must not just leave, but leave with a purpose, otherwise the opponent will have time to defend. Ideally with a check, an attack or a capture.

How to find a clearance

  1. Find the winning idea: a mating square, an open line for a rook or queen.
  2. Work out which of your own pieces is in the way: it stands on the square you need or blocks the line.
  3. Find a move with tempo for it (a check, a capture, a threat) so it can leave without losing the initiative.
  4. Check that the main idea now works and the opponent has no time to defend.

Tips to spot the idea faster

For kids

Imagine you want to put your "hero" on a magic square, but your friend is already standing there. First you need to ask your friend to step aside, ideally so that they do something useful on the way.

In chess, "useful" means a check or a capture.

For adults

Clearance is often close to a discovered attack: one piece leaves, and another gets freedom of action. The difference is who exactly needs the "free" square.

In positions with two rooks on the same line, clearance often means shifting the rooks: one is sacrificed so that the other can go deeper.

Examples

Try it yourself: make a move on the board. If you get stuck, press "Show solution".

1. The bishop leaves the file: the rook wins the queen

Idea: the white rook on e1 wants to strike along the e-file at the queen on e7, but its own bishop on e4 is in the way.

1.Bxh7+! - the bishop leaves the file with check and a capture. For example, after 1...Kxh7 the e-file is open, and 2.Rxe7 wins the queen. On 1...Kf8 it is also 2.Rxe7 Kxe7: White gets the queen for a rook.

Solution: 2.Rxe7 - the e-file is open, and the rook wins the queen. On 1...Kf8 it is also 2.Rxe7 Kxe7: the queen is lost for a rook.

2. The pawn leaves with a capture: the rook breaks onto the file

Idea: the white pawn on e4 blocks its own rook on e1 from the queen on e8.

1.exd5! - the pawn leaves by capturing the knight. The e-file opens, the rook attacks the queen, and Black has no time to win the piece back: on 1...cxd5? comes 2.Rxe8#. Black loses both time and material.

Solution: 1.exd5! - the e-file is open, and the rook attacks the queen on e8. There is no time to win the knight back: on 1...cxd5? comes 2.Rxe8#.

3. The knight vacates a square for the queen

Idea: the white knight on h7 is standing exactly on the mating square where the queen wants to go. If the knight simply moves away, the opponent will regroup (besides, the knight on f6 attacks the queen on h5). The knight has to leave with tempo.

1.Nxf6+! - the knight leaves with a capture and check. After the forced 1...gxf6 comes 2.Qh7#: the queen steps onto the vacated square, protected by the bishop on d3.

Solution: 2.Qh7# - the queen takes the vacated h7 square, protected by the bishop on d3. Mate.